Wireless communication systems, such as cellular voice and data networks, typically include multiple wireless access nodes spread over a geographic area. As a result, wireless communication devices can register at various wireless access nodes and access communication services. In many examples, the wireless communication devices are mobile, and can move between wireless coverage areas of the wireless access nodes. As a result, people can use cellular telephones in a wide variety of locations and can make calls while moving or traveling.
Continuous cellular telephone service is available through handoffs, wherein an active cellular telephone can move from cell to cell in a cellular network. The cellular network hands off the cellular telephone from one base station to the next. As a result, a user receives continuous and uninterrupted service.
A handoff may occur where the cellular telephone is moving from one cell to the next and a handoff must be performed for the cellular telephone to maintain communications. Alternately, a handoff may occur where a cellular telephone is in a region overlapped by another cell and the cellular telephone is handed off to provide more capacity in the cell. In another alternative, a handoff may occur where a cellular telephone is experiencing interference in a current cell and is handed off to a neighboring cell to reduce interference.
In a handoff, an adjacent cell will be using a different set of frequencies in order to avoid interference. Consequently, during a handoff process, the cellular telephone must negotiate with both a current cell and a next cell over the transfer of service. Issues that must be addressed are the identity of the cellular telephone and the traffic load/capacity of the next cell, for example.
Emergency telephone calls may be received in a wireless network. Emergency systems have been implemented that handle and facilitate emergency telephone calls, such as Enhanced 911 (E911), Next Generation 911 (NG911), and Wireless Priority Service (WPS), for example. In the event of an emergency telephone call being received in a wireless network, the emergency telephone call should be given a high priority. This includes facilitating handoffs of the emergency telephone call between cells of the wireless network.